国外长壁开采系统在七十年代的一个重大发展是采煤机的无链牵引。目前,西德60％的滚筒采煤机使用无链牵引系统,英国1977年有87个工作面使用无链牵引系统,1979年已增加到124个。 无链牵引系统由于加设了附加牵引部,使牵引力成倍增加(可达46吨),因而满足了采煤机在大倾角(达64°)时所需的大牵引力的要求,从而扩大了无链牵引采煤机的使用范围。现在,无链牵引采煤机可用于中 One of the major developments of longwall mining systems in the late 1970s was chainless traction of shearer. Currently, 60% of West Germany’s drum shearers use a chainless traction system. In 1977, there were 87 work surfaces in the United Kingdom that used a chainless traction system, up from 124 in 1979. The chainless traction system has doubled traction (up to 46 tons) due to the addition of additional traction, thus meeting the high traction requirements of shearer at steep angles up to 64 °, expanding Chain-free traction shearer range of use. Now chainless haulage shearers are available